In the Arctic’s short summer growing season, timing is everything. From snowmelt to senescence, tundra plants race to send out their annual set of leaves, flowers, and fruit before the winter. But as climate change extends Arctic summers, some plants appear to be better able to respond, staying green for longer. Researchers at Toolik Field Station want to know how well tussock cottongrass can adjust to the longer growing season—and what that may mean for the tundra at large.